The major objective of this project is to investigate the mechanism of cataract induction and explore the possibility of preventing, delaying or regressing the lens opacity induced by cataractogenic agents. In our laboratory morphological (light, transmission and scanning electron microscopy) and ultrastructural cytochemical approaches are being used to investigate alterations in rat lenses induced with galactose. Moreover, our laboratory is also interested in studying morphological and cytochemical bases for regression of galactose-induced lens intraparency. Our initial cytochemical work involved localization and quantitation of two key enzymes, Na-K-ATPase and acid phosphatase in the lens during the process of cataractogenesis and several of opacities (tissue repair). We have recently initiated our efforts to investigate the effect of hormones on galactose cataractogenesis. Our investigations to date have already provided results which provide better understanding of the mechanisms of sugar cataract initiation, progression and regression. Results from some of our initial studies warranted development of new approaches to obtain further understanding of this ocular disease. The proposed program outlines our new direction. We also propose to study cataracts induced by X-rays using the above-stated parameter.